McCauley races against time in order to save an astronaut who is trapped when assembling the prefabricated units of a space station. The astronaut is the son of a air force general and trapped when his sleeve catches between sections of the space station.

When an astronaut is stricken by a heart attack on the Moon, McCauley must find a way to get him back to Earth.

A scientist's wife warns McCauley that her husband Perry's's co-worker Hal Carter is jealous of his success. McCauley doesn't believe her, but when Perry's theory about radioactive gas on the moon prove correct, Hal plots to kill Perry.

Ship MR34 loses Auto-Control during landing and crashes 200 miles from Moon Base. Two of the crew survive and make for a nearby fuel-cache. Can they use the liquid oxygen there to improvise a survival igloo?